Men's Grand Slam matches are brutal best-of-five affairs, tests not just of skill but endurance and mental fortitude. And at least one tennis legend is suggesting that they've outlived their usefulness.

Martina Navratilova, who's won 18 Grand Slam singles titles of her own, said that men's matches could switch to best-of-three sets in the future in order to prevent injury. "It's really becoming so taxing that I believe one day we will have two out of three sets in the Grand Slams, otherwise they're going to be taking people out on stretchers," Navratilova said. Her comments came in an interview with Laureus.com, the online arm of a charitable sports organization devoted to using sports to promote social change.

Navratilova noted that many major names have suffered significant injuries in recent months, including Rafael Nadal, Novak Djokovic, and Andy Murray. The question, of course, is whether these injuries have any common thread, and Navratilova believes there are several.

"Number one, we’re playing on hard surfaces most of the year, not clay," she said. "We used to play with wood and gut, now they play with metal or some kind of synthetic racket. They put a lot more hours in and everybody hits the ball harder, you have to run harder. Plus the courts are slower so the rallies take longer. This has to take its toll on the body. You play a long match and it takes you months to recover, because it’s like running a marathon in sprints, but then sometimes you have to go out and play a match the next day or two days later."

The answer? Best-of-three sets, not best-of-five. To the purists who want to preserve traditional format, Navratilova noted that tie-breakers only date to the '70s.